Improvement in steam-genebatobs



@uiten A? faire geirrtr @frn JOHN N. SNOWDON AND HENRY W1LK1NS, OF BROWNSVILLE, PENN- SYLVANIA.

Letters Patent No. 68,663, dated September 10, 1867.

IMPROVEMENT IN STEAM-GENERATORS.

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T0 ALL WHOM IT MAY CONCERN:l

Be it known that we, JOHN N. SNOWDON and HENRY WILKINS, of Brownsville, in the county of Fayette,

and State of Pennsylvanial have iventedn new and useful Improvement in Apparatus for Heating Feed-Water for Boilers; and we do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings, making a part of this specification, in which- Figure is a longitudinal vertical section of a fined-steam boiler, and Figure 2 is a transverse section, showing the feed apparatus, mud-drum, rear end of the'boiler, etc.; and Figure 3 is a vertical section through the check-valve. Like letters of reference refer to similar parts of" each. The nature of our invention consists in the arrangement of the feed-water pipes of a steam-boiler, such that the water shall be heated to n temperature equal or nearly equal to that of the water in the boiler before, -entering the boiler. r

Toenable others skilled in the art to make and use our invention, we will proceed to describe itsconstrnction and operation. f

In Ordinary lined-steam boilers the heat passes from the vlire under the front of the boiler n along the passage e to the rear, thence up the chamber y, entering the boiler ues z z', passing through them the entire length of the boiler and out into the chimney. In our invention the water pipe a passes through the side wall of the boiler furnace into the chamber y at the rear of the boiler, thence across such chamber in a direction horizontal, `or nearly so, thence back, and so back and forth, substantially as represented by b b b", etc., a suicient number of times to insure the heating of the water therein to the desired temperature. The pipe a then passes through the foundation m, and by a check-valveat d communicates with the mud-drum e, which Opens into the boiler n by the stand pipe o. By a doctor, force-pump, injector, or other Equivalent device, We force the Water along the pipe a through the zigzag series of pipes b b b", etc., where it becomes heated to the desired temperature by heat from the lire, as above described. It is then driven through the check-valve d into-the mud-drum e, whence it supplies the'fboiler through the stand pipe o. The check-valve d is of the ordinary construction, and opens upward or toward the boiler n to admit Water when forced in, 'as above described, and on the pressure in that direction being removed closes to prevent the water in the boiler from escaping into or through the heating pipes b vl5 Za, etc. As pipes in the chamber of a furnace, when running parallel` to each other, near together,

and one above the other, are liable to become covered and their interstices to be filled with ashes, soot, or o ther impurities, we usually arrange them under each other alternately in two or more vertical rows, as shown in fig. 1, b coming under 6,'5 under b', and so through the series. In this way also we secure a more uniform application of the heat to the outer surface'of the feed pipes, and consequently a more uniform expansion and contraction of the pipes as the heat is increased or diminished. The ordinary method of constructing a series of zigzag pipes, such as b I1 f, etc., and the method by which We generally construct them is'to join them at or near the points `c c by elbows, thc joints being made water-tight by cement, solder, screw-thread, or other device commonly in use. To prevent such joints from boing injured by the heat we usually` build them into the side Waller let them into recesses, as shown in fig. 2, and cover the `joints with brick and mortar, or other material` adapted to the purpose. It sometimes becomes necessary to dran' oil` thc water from the heating pipes described, particularly during very cold weather, when, if the tire is allowed to go out for any causo, the pipes a b b, etc., if full, would bc in danger of being bursted by the expansion ofthe water in freezing. In such case the Water may be drawn ot by a stop-cock of the ordinary construction inserted at any convenient point; but as the empty pipes would be liable to great injury from being overhcatcd when the fire is renewed, before steam could be raisedto ll them again, we commonly ll them from the water in thc boiler, introducing for this purpose a pipe, j', leading from the mud-drum e to tbe\fecd pipe atg back of the check-valve d. In this pipe f we fit a. stop-l cock, h, of the ordinary construction. This being opened, the water from the boiler n ilows into the empty pipes b b', etc. When they are lilled the stopfc'ock 7i is closed, the re kindled, steam raised, and water supplied to the boiler in the manner above described. By these devices we feed Water into the boiler, heated toa temperature equal or nearly equal te the temperature of the water already in the boiler, and thereby avoid the evils necessarily attendant on` introducing water at a low temperature into a boiler heated to'a high temperature.

We'coinmonly use tlle devices above described in connection with an injector, and in such case the amount of steam necessary to operate the injector and feed-ivater into the boiler is considerably less than what is required when the Water is fed directly into the boiler Without having been previously heated, or is heated in pipes which are arranged wholly or chiefly inside the boiler. In other Words, under -the circumstances above sta-ted, a less amount'of steam carries the same quantity of water into the boiler, or with the same amount and pressure of steam on the injector the flow of water into` the boiler is greatly increased. This fea-ture of our invention is an important one, as it adds greatly to the practical efficiency and utility of the injector. The arrangement of pipes above described wc employ'also in connection with the cylindrical boiler. In such case the heat from the fire passes into the chamber y, as above described, and thence directly 'or by pipes or other device into thechimney or stack. Y YThe shape and' general construction o'f the chamber y are not materially altered thereby, except to afford an exit to the chimney or stack for the smoke, gases, and surplus heat, and hence the arrangement-of the feed pipes hereinbefore described will in such case be substantially the same. The chamber y must, however, in all cases, be constructed of suiiicient size to afford room for such a series of pipesas those above described.

` We do not limit ourselves in our invention to the arrangement ofihorizontal pipes alone, as we place suoli pipes at anydesirable angle to each other or tothe walls which enclose them, or construct them in the form of a coil of any desirable shape.

Having thus described our invention, what We claim, isv The arrangement of a. series oi' zigzag or coiled feed-waterpipes in the heating-chamber y of the rear end of av steam-boiler, substantially as and for the purposes set forth. I

In testimony whereof` We, the said JOHN N. SNoWDoN and-HENRY WILKINS, have hereunto set our` hands in presence of JOHN N. SNOWDON,

HENRY WILKINS. Witnesses A. S= NICHOLSON, Geo. H. CHRsTY. 

